I've had some pretty nice shooting factory rifles but when you get to build something you get to select action,barrel,barrel twist,barrel length, how you want the rifle throated maybe for a certain bullet,stock,length of pull, trigger and weight of rifle,fluted barrel or not same with bolt etc. When you buy a factory rifle you are buying something somene hope you will like when you have something build you are building something you want using your skills to select the right products. Of course a good gunsmith helps.
I always figure when I have something build I'm just testing my shooting skills to a different level. I spend alot of time looking at bullets,barrel twist and what case would work best.
Hard to say which would be best for you. Cost alot of money to have one build, can bed an existing rifle and rebarrel for alot less. If your looking to build one for this year might want to talk to your gunsmith and see what his time frame is. Well good luck